WASHINGTON – A Utah soccer referee who died Saturday from injuries suffered after being punched in the head is a tragic example of the increasing dangers in officiating the sport, according to veteran referees.

“It seems like it’s more acceptable for players and spectators to act out with the foul language and the misbehavior,” says John Schmitz, who says he’s refereed about 8,000 soccer matches in his 25-year career on both the amateur and professional levels.

Ricardo Portillo had been in the hospital since April 27. According to KSL-TV in Utah, he suffered extreme swelling of the brain, blood loss and bleeding around the blood vessels in one area of his brain.

The Associated Press reports the 17-year-old goalie accused of hitting Portillo was booked into juvenile detention on suspicion of aggravated assault. Authorities will consider additional charges since Portillo has died.

Schmitz, who lives in Springfield, Va., and has a Ph.D. in history, understands soccer can set off the emotional sensors in fans. But at times, he says, the line between passionate enthusiasm and criminal activity is crossed.

“A president of one of our amateur leagues threatened me, threatened to get my wife and find out where I lived,” he says.

Players have thrown bottles at Schmitz from the bench and in one instance, he says a fan came onto the field wielding a knife.

“I had my arms outstretched trying to protect the player who instigated everything and I realized I had my body between the fan and him,” says Schmitz.

“Later on I realized that wasn’t the smartest thing.”

Tim Daly had nine years of altercation-free refereeing until December of 2012. During a championship match, Daly says he gave a player a red card, which meant the player was ejected from the match.

“That player then turned around, began yelling at me in a foreign language, and ultimately spit at me,” Daly says.

Daly filed a report with the Metropolitan D.C.-Virginia Soccer Association (MDCVSA), with which he’s certified. Once his complaint was accepted, the player was suspended from all MDCVSA and U.S. Soccer Federation leagues for six months.

Jim Sadowski, president of the MDCVA, says incidents like Daly’s are rare in affiliated leagues.

“In the affiliated leagues there are procedures and processes, and they tend to weed out the bad teams and the bad officials for that matter,” says Sadowski, who’s also a national referee.

Daly also says he believes the problems are minimal because players largely take ownership of their actions.

“A lot of the players will police themselves,” says Daly. “They know that their actions will have consequences.”

Portillo reportedly was officiating in a non-sanctioned game in Utah. The CEO of the Utah Youth Soccer Association told The Salt Lake Tribune the game was part of a “rogue league” that was not affiliated with an association or town department.

Sadowski says if Portillo was part of his organization and claimed he was assaulted while refereeing a non-sanctioned game, he would be out of luck.

“There’s nothing we can do to help them, because it’s an unaffiliated match and we don’t have any jurisdiction over that,” he says.

Schmitz says while he’s been in some dangerous situations on the field, 95 percent of the time there are no issues at all.

However, he says it only takes one knife-toting fan to overshadow the otherwise organized event.

“It’s the 1 in 100, 1 in 1,000 cases that can really scare you,” he says.

WTOP’s Max Smith contributed to this report. Follow @amaxsmith and @WTOP on Twitter.